GERMINATION OF TREE-SEEDS. DORMANCY.

It is well known that it is more difficult to germinate seeds of perennial plants than annual plants, and among these the tree-seeds form a special group, which gives the nurseryman and the scientist great problems.

To make a seed germinate it must be placed under convenient germination conditions: Water, proper temperature, light and air.
Germination in seed plants may be defined as the sequential series of morphogenetic events that result in transformation of an embryo into a seedling and can be described as follows:

1. The seeds absorb water.

2. The seeds produce small quantities of gibberellic acid.

3. The GA diffunds into the aleuron cells and induces a formation of enzymes.

4. The enzymes penetrate the endosperm (or cotyledons) and split the starch into soluble carbo-hydrates which are used as energy for the embryo-development.

Most seeds of Picea and Pinus species will germinate very quickly under convenient germination conditions, while seeds of Abies species and many broad-leafed trees often fail to germinate or develop very sluggishly.

Symposium on Propagation in Arboriculture

I. Nyholm

https://doi.org/10.17660/ActaHortic.1975.54.2